When a photograph is taken by a photograph device, an orientation in which the length direction of an image is approximately horizontal (landscape) or an orientation in which the length direction of an image is approximately vertical (portrait) can be selected according to the object to be photographed and the like. As a result, there is a need among users to take a photograph in a desirable image orientation even when a stereoscopic image photograph is taken which has a parallax equivalent to or close to a binocular parallax.
A technique is known that provides multiple imaging units in a photograph device such that a configuration of the photograph device can rotate around a photograph optical axis of each imaging unit according to the orientation of the image to be photographed (Japanese Laid-open Patent Publication No. 1998-224820, Japanese Laid-open Patent Publication No. 2009-177565).
Furthermore, a related technique is known in which a photograph device that is provided with a monocular imaging unit is equipped with a triaxial acceleration sensor. The device detects a panning operation based on the sensor output and recognizes the orientation of the image to be photographed (Japanese Laid-open Patent Publication No. 2009-103980).